2014 Forecasted Corn Yields Based on July 20 Hybrid Maize Model Simulations

Corn is pollinating throughout Nebraska or will be shortly. Questions are being asked about how this year's weather to date has impacted expected yield and the most likely weather scenario for the rest of the 2014 growing season. Since 2011, we have run in-season corn yield predictions using the Hybrid-Maize Model developed by researchers in the Department of Agronomy and Horticulture at UNL.

The Hybrid-Maize model simulates daily corn growth and development and final grain yield under irrigated and dryland conditions. This model estimates "yield potential," which is the yield obtained when the crop is not limited by nutrient supply, diseases, insect pressure, or weed competition — conditions that represent an "optimal management" scenario. It also assumes a uniform plant stand at the specified plant population and no problems from flooding or hail. Because weather and management factors are "location-specific," Hybrid-Maize simulations are based on actual weather data and typical management practices at the location being simulated.

The Hybrid-Maize model can be used during the current crop season to forecast end-of-season yield potential under irrigated and dryland conditions. To do so, Hybrid-Maize uses observed weather data until the date of the yield forecast and historical weather data to predict the rest of the season, which gives a range of possible end-of-season yields. This simulated range by Hybrid-Maize narrows as corn approaches maturity. Hybrid-Maize helps us understand

• how current in-season weather conditions affected corn growth up to the date of the simulation and
• the most likely scenarios for completing the growing season.

Hybrid-Maize then compares these projections with actual data from previous years.

Simulations of 2014 end-of-season corn yield potential at 25 locations across the Corn Belt were performed on July 20 (Figure 1). Separate yield forecasts were performed for irrigated and dryland corn for those sites in Nebraska and Kansas where both irrigated and dryland production are important. Input data used for the simulations include weather data provided by the High Plains Regional Climate Center (HPRCC), the National Weather Service (NWS) station network, the Illinois Water and Atmospheric Resources Monitoring Program (WARM), the Ohio State University, Ohio Agricultural Research and Development Center (OARDC) Weather Service, and the University of Wisconsin Extension Ag Weather.